<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            position: relative;
            width: 400px;
            border-bottom: 1px solid #ccc;
            margin: 100px auto;
        }
        
        .box input {
            width: 370px;
            height: 30px;
            border: 0;
            outline: none;
        }
        
        .box label {
            position: absolute;
            top: 0;
            right: 0;
        }
        
        .box img {
            width: 24px;
        }
    </style>
</head>

<body>
    <div class="box">
        <label for="">
            <img src="images/close.png" alt="">
        </label>
        <input type="password" name="" id="">
    </div>
    <script>
        var input = document.querySelector("input");
        var label = document.querySelector("label");
        var img = document.querySelector("img");
        var flag = 1;
        label.onclick = function() {
            if (flag == 1) {
                img.src = "images/open.png";
                input.type = "text";
                flag = 0;
            } else {
                img.src = "images/close.png";
                input.type = "password";
                flag = 1;
            }
        }
    </script>
</body>

</html>